P 3 K Stimulus Design Update PALM-3000 Rick

P 3 K Stimulus Design Update PALM-3000 Rick Burruss P 3 K Team Meeting #7 February 27, 2008

PALM-3000 Current Stimulus

PALM-3000 • Requirements Overview Highlights from the Stimulus Requirement Document (St. RD) version 1. 1 (12/11/07) – There shall be a source that produces light over the entire spectrum used by the instrument (0. 4 -2. 2 um) that can be located at the equivalent of the telescope image plane (Science source) – There shall be a source that produces light at 589 nm +/-10 nm that can be located at the equivalent of 90 km focus (LGS source) P 3 K-IRD-0465 – There shall be a source that is bright enough to be visible to the eye at full beam size (4. 5” diameter) that can be located at the equivalent of the telescope image plane (Alignment Mode) – At least one source shall have a pupil stop at the location of the telescope pupil image – The Science source shall be adjustable in focus by +/-25 mm – The Science source shall have a translation range of +/- 10 mm in the x and y directions – The LGS source should be adjustable in focus from the equivalent of 80 to 120 km – Stimulus shall have a seeing-size effective spot size of 0. 5 -1” for NGS – All sources shall have variable intensity – The stimulus package shall be configured such that the LGS and Science sources can be used at the same time – The stimulus package shall fit within current box

Optical Design Top View PALM-3000 White Light Aerotech Stages X, Y, Z 594 Laser Aerotech Z Stage 80: 20 Beamsplitter OAP 1 Pupil Mask Flipper Beam Entrance Hole (old fold mirror) FM 2 FM 1 OAP 2 Conjugate Telescope Focus

PALM-3000 The New P 3 K Stimulus • All reflective design; pupil shared by all 3 sources • We will re-use 3 pieces of the current stimulus 1. The white light source and fiber in the rack 2. The He. Ne alignment laser 3. The fold mirror (and Newport motor) on the AO bench will be retained in its current location and height • All other pieces in the current stimulus package will be removed

Rack Design Front View PALM-3000 New additions are in RED Newport Versastar 0. 5” filter wheel c = 1550 nm c = 460 nm

PALM-3000 • Light Source Issues White Light Source magnitudes – R-band (WFS) = 2. 3 – K-band (Pharo) = -0. 3 – The new white light will be 30% fainter than the old white light due to beamsplitter and reflective surface loss • The 632 nm alignment laser will project in multi mode when using the white light fiber (2 lobes in V-band), although most of the light (>85%) remains in the core of the fiber output. • The 632 nm alignment laser may be used as a single mode alignment source through the 594 nm laser fiber with the 594 fiber output Aerotech stage set to 0 km. • The 2 laser source intensities may be reduced by using a combination of neutral density filters mounted in a manually selectable filter wheel placed at the output of both lasers.

594 and 632 Magnitudes PALM-3000 For the 594 and 632 nm laser magnitudes of the new design, we calculated the overfill loss at the pupil in the stimulus, assumed 20% loss at the fiber couple, 2% loss at each optical surface, and an 80: 20 beam splitter at the 594 nm input Source Fiber Used (mode) ND Used Mag @ WFS 594 (single) None -8. 5 594 (single) 4. 0 1. 5 594 (single) 4. 0 + 2. 0 6. 5 594 (single) 4. 0 + 3. 0 9. 0 594 (single) 4. 0 + 4. 0 11. 5 632 * 594 (single) None -9. 6 632 * 594 (single) 4. 0 + 4. 0 10. 4 632 White Light (multi) None -9. 3 632 White Light (multi) 4. 0 + 4. 0 10. 7 * The 594 nm laser stage must be moved to 0 km for 632 source alignment

PALM-3000 Science Focal Spot Diagrams • 450 to 2200 nm Spot Diagram at center, +/- 1 mm, and +/- 10 mm

PALM-3000 Alignment Tolerances • Stimulus source total wavefront error requirement = 300 nm / (2)1/2 = 212 nm • OAP vendor (B-Con) guarantees /4 with best effort to /8. /4 OAP fabrication surface error results in 112 nm wavefront error for 2 OAPs • Final wavefront error = [(alignment errors)2 + (fabrication errors)2]1/2 = 212 nm • Wavefront error from alignment will not exceed 180 nm to satisfy total wavefront error requirement

PALM-3000 Cable / Controller Additions • The existing Aerotech EPAQ controller will be modified to run 7 stages (it currently controls 3 stages) • The 4 new Aerotech stages in the stimulus will connect to the existing Aerotech controller via 4 10 meter cables, which will be bundled together

PALM-3000 Stimulus Cover Handles Pupil Access Output opening Side Pupil Access

Final Cost List PALM-3000 Name Quantity Vendor Cost 2 OAP mirrors 2 B-Con (total) 6750 X, Y stages (ATS-50 -25) 2 Aerotech (total) 8295 460 nm cutoff fibers (2 m and 5 m) 2 Thorlabs (total) 166 460 nm cutoff fiber (10 m) 2 Thorlabs (total) 336 ND filter wheel hub 1 Newport ND holders (12. 7 mm diam x 10 mm thick) 5 Newport 2. 0 ND filter (12. 7 mm diam x 2 mm thick) 1 Thorlabs 20 3. 0 ND filter (12. 7 mm diam x 2 mm thick) 1 Thorlabs 20 4. 0 ND filter (12. 7 mm diam x 2 mm thick) 5 Thorlabs (total) 100 OAP Gimbal Mounts (Bartos - FQPM) 2 In House (total) 500 80: 20 beamsplitter 1 CVI 310 Fiber Coupling Hardware 1 Thorlabs 516 Pupil flipper mount 1 New. Focus 248 Mechanical Fabrication of Pupil Mask 1 JPL (Bartos) 200? Mechanical Fabrication of Cover 1 Caltech (Bui) 2000? 109 (total) Total Items in hand are green, items on order are blue 145 $ 19715

PALM-3000 • Pencil Beam A pencil beam laser source, a fold mirror, and a magnetic kinematic mount will be permanently added outside of the stimulus cover for AO lab testing. These additions will not vignette any part of the stimulus beam nor will they block the off-axis relay mounts. The second fold mirror will be permanently fixed to the magnetic mount’s twin for quick and easy assembly. Permanent Mount Temporary Fold Permanent Laser Permanent Fold

PALM-3000 Phase Screens • During the design review, CD jewel case covers were suggested as a simple costeffective method to generate various spot size disks in the output beam of the stimulus. • Once the stimulus is working, we can try this • The 6” diameter door on the top of the cover should allow easy access and jewel case placement (pieces of plexi-glass? )